1. Field of the Invention
This invention relates to low reflective transparent polyermic film.
2. Discussion of Prior Art
The transparency of windows, show cases, glass, viewers or video screens can be effected by glass, reflective light sources, or the reflection of surrounding scenery. In order to ameliorate the problem with glare and reflections, anti-reflective coatings have been developed which are typically applied to a surface by vapour deposition or sputtering methods.
Another method for depositing anti reflective coatings is disclosed in U.S. Pat. No. 4,687,707 in which the coating is formed from a thin layer of a reaction product containing a metal oxide e.g. SiO.sub.2 or TiO.sub.2. Such a product results from the condensation of titanium tetra-alkoxides, titanium chelates or tetraalkoxy silanes. To this layer, is added a second layer of a condensation product containing a fluorine compound such as fluorine containing silane compounds. This multi layer construction bringing about an improvement in the reduction of reflectance.
U.S. Pat. No. 4,966,812 discloses the deposition of a low refractive index anti-reflective coating on plastics material using sol-gel techniques. U.S. Pat. No. 5,109,080 discloses a high refractive index ceramic/polymer material which is made from a sol-gel synthesis of a metal alkoxide with an alkoxysilane-capped poly(arylene ether) polymeric component.
EP 0166363 discloses the use of at least two thin layers as a low reflective coating, a first layer containing metal oxide and having a refractive index in the range of 1.65-2.10, and a second over layer comprising a fluorine-containing silicon compound making a low refractive index having a refractive index of about 1.4.